import numpy
import unittest
from theano.tests import unittest_tools as utt
import theano
import theano.tensor as tt


class Test_inc_subtensor(unittest.TestCase):
    """Partial testing.

    What could be tested:
    - increment vs set
    - thing incremented: scalar, vector, matrix,
    - increment/set: constant, scalar, vector, matrix
    - indices: scalar vs slice, constant vs variable, out of bound, ...
    - inplace

    NOTE: these are the same tests as test_incsubtensor.py, but using
    the new (read: not deprecated) inc_subtensor, set_subtensor
    functions.

    """
    def setUp(self):
        utt.seed_rng()

    def test_simple_2d(self):
        """Increments or sets part of a tensor by a scalar using full slice and
        a partial slice depending on a scalar.
        """
        a = tt.dmatrix()
        increment = tt.dscalar()
        sl1 = slice(None)
        sl2_end = tt.lscalar()
        sl2 = slice(sl2_end)

        for do_set in [False, True]:

            if do_set:
                resut = tt.set_subtensor(a[sl1, sl2], increment)
            else:
                resut = tt.inc_subtensor(a[sl1, sl2], increment)

            f = theano.function([a, increment, sl2_end], resut)

            val_a = numpy.ones((5, 5))
            val_inc = 2.3
            val_sl2_end = 2

            result = f(val_a, val_inc, val_sl2_end)

            expected_result = numpy.copy(val_a)
            if do_set:
                expected_result[:, :val_sl2_end] = val_inc
            else:
                expected_result[:, :val_sl2_end] += val_inc

            self.assertTrue(numpy.array_equal(result, expected_result))

    def test_simple_3d(self):
        """Increments or sets part of a tensor by a scalar using full slice and
        a partial slice depending on a scalar.
        """
        a = tt.dtensor3()
        increment = tt.dscalar()
        sl1 = slice(None)
        sl2_end = tt.lscalar()
        sl2 = slice(sl2_end)
        sl3 = 2

        for do_set in [True, False]:
            print "Set", do_set

            if do_set:
                resut = tt.set_subtensor(a[sl1, sl3, sl2], increment)
            else:
                resut = tt.inc_subtensor(a[sl1, sl3, sl2], increment)

            f = theano.function([a, increment, sl2_end], resut)

            val_a = numpy.ones((5, 3, 4))
            val_inc = 2.3
            val_sl2_end = 2

            expected_result = numpy.copy(val_a)
            result = f(val_a, val_inc, val_sl2_end)

            if do_set:
                expected_result[:, sl3, :val_sl2_end] = val_inc
            else:
                expected_result[:, sl3, :val_sl2_end] += val_inc

            self.assertTrue(numpy.array_equal(result, expected_result))

    def test_grad_inc_set(self):
        def inc_slice(*s):
            def just_numeric_args(a, b):
                return tt.inc_subtensor(a[s], b)
            return just_numeric_args

        def set_slice(*s):
            def just_numeric_args(a, b):
                return tt.set_subtensor(a[s], b)
            return just_numeric_args

        for f_slice in [inc_slice, set_slice]:
            # vector
            utt.verify_grad(
                    f_slice(slice(2, 4, None)),
                    (numpy.asarray([0, 1, 2, 3, 4, 5.]),
                        numpy.asarray([9, 9.]), ))

            # matrix
            utt.verify_grad(
                    f_slice(slice(1, 2, None), slice(None, None, None)),
                    (numpy.asarray([[0, 1], [2, 3], [4, 5.]]),
                        numpy.asarray([[9, 9.]]), ))

            #single element
            utt.verify_grad(
                    f_slice(2, 1),
                    (numpy.asarray([[0, 1], [2, 3], [4, 5.]]),
                        numpy.asarray(9.),))

